Commit c669c014 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Add jiffies-since-GP-activity to show_rcu_gp_kthreads() 



This commit adds a printout of the number of jiffies since the last time
that the RCU grace-period kthread did any processing.  This can be useful
when tracking down forward-progress issues.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent 69196019

kernel/rcu/tree.c

+5 −3
Original line number Diff line number Diff line
@@ -515,12 +515,14 @@ static const char *gp_state_getname(short gs) 
void show_rcu_gp_kthreads(void)

{

	int cpu;

	unsigned long j;

	struct rcu_data *rdp;

	struct rcu_node *rnp;



	pr_info("%s: wait state: %s(%d) ->state: %#lx\n", rcu_state.name,

		gp_state_getname(rcu_state.gp_state), rcu_state.gp_state,

		rcu_state.gp_kthread->state);

	j = jiffies - READ_ONCE(rcu_state.gp_activity);

	pr_info("%s: wait state: %s(%d) ->state: %#lx delta ->gp_activity %ld\n",

		rcu_state.name, gp_state_getname(rcu_state.gp_state),

		rcu_state.gp_state, rcu_state.gp_kthread->state, j);

	rcu_for_each_node_breadth_first(rnp) {

		if (ULONG_CMP_GE(rcu_state.gp_seq, rnp->gp_seq_needed))

			continue;